Man has anchored boats, tethered beasts, stabilized man-made structures, and attached objects to walls and ceilings since the dawn of time. To this end, he has invented a wide variety of devices for immobilizing objects.
The first water anchors were simply heavy stones attached to vessels by ropes. Later anchors were made of wood, and then metal, and were variously shaped to better burrow into the seabed and to clasp underwater rock formations. Alternatively, vessels were also tethered to fix posts anchored to land, for example dock pylons.
A number of designs for anchoring boats and other objects have been reported. U.S. Pat. No. 3,187,705 describes a boat anchor having an internally mounted shaft to penetrate the ocean floor with outwardly extending legs for embedding within the floor and maintaining secure anchoring. U.S. Pat. Nos. 4,960,064, 5,613,458, and 6,606,829 disclose a spike-like anchor having a drive anvil and hammer; the pointed lower end of an anchor rod is placed in contact with the ground and the hammer repeatedly strikes the drive anvil, driving the anchor rod into the ground. U.S. Pat. No. 3,427,812 discloses an apparatus for securing a pipe to the earthen surface underlying a body of water, which includes an anchor-driving device and an anchoring assembly. U.S. Pat. Nos. 3,841,105, 3,479,830, 4,389,034, 4,492,493, 5,730,552 and 6,066,015 disclose the use of screw-type elements that are embedded into the earth's surface underwater. U.S. Pat. Nos. 4,265,566, 4,626,330, 5,653,069, 5,881,978 and 5,934,839 disclose various types of anchors driven into the earth's surface underwater and on land. U.S. Pat. No. 5,501,551 describes anchors having a radially expansible shell. U.S. Pat. Nos. 4,634,326 and 5,439,330 describe anchors having an expansion member.
Existing water anchors have several disadvantages. They typically must be blindly dragged through a seabed, wreaking havoc to undersea habitats such as coral colonies, until an anchor either sinks in the sand or grips a rock. It is frequently frustratingly necessary to attempt to set an anchor several times before succeeding. All too often, wind or current moves an anchored vessel and dislodges the anchor, thus unpredictably setting the vessel dangerously adrift. Lifting anchor can be problematic because current anchors, once lodged, tend to hold fast, and often it is necessary to cut the line and lose the anchor. When successfully retrieved from the bottom of a body of water, conventional anchors typically carry mud, grass or other debris up with them. The debris must at the least be cleaned from the boat, and at the worst may damage the boat or any items inside the boat.
As will be seen more fully below, the present invention is substantially different in structure, methodology and operation from that of known anchors. This invention overcomes noted disadvantages of prior water anchors. Certain embodiments are also useful for anchoring a variety of objects on land.